Texas Instruments UCC3580EVM User manual

User Guide
1
UCC3580EVM Flyback Converters,
Active Clamp vs Hard-Switched
Evaluation Board and List of
Materials
User’s Guide

2
EVM IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION
PURPOSES ONLY and is not considered by TI to be fit for commercial use. As such, the goods being provided
may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective
considerations, including product safety measures typically found in the end product incorporating the goods.
As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic
compatibility and therefore may not meet the technical requirements of the directive.
Should this evaluation kit not meet the specifications indicated in the EVM User’s Guide, the kit may be returned
within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE
WARRANTY MADE BY SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED,
IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user
indemnifies TI from all claims arising from the handling or use of the goods. Please be aware that the products
received may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). Due to the open construction
of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic
discharge.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE
TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not
exclusive.
TI assumes no liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein.
Please read the EVM User’s Guide and, specifically, the EVM Warnings and Restrictions notice in the EVM
User’s Guide prior to handling the product. This notice contains important safety information about temperatures
and voltages. For further safety concerns, please contact the TI application engineer.
Persons handling the product must have electronics training and observe good laboratory practice standards.
No license is granted under any patent right or other intellectual property right of TI covering or relating to any
machine, process, or combination in which such TI products or services might be or are used.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2001, Texas Instruments Incorporated

3
EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the input voltage range of 0 VAC to 135 VAC and the output voltage
of 0 VDC to 14 VDC.
Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM.
If there are questions concerning the input range, please contact a TI field representative prior to connecting
the input power.
Applying loads outside of the specified output range may result in unintended operation and/or possible
permanent damage to the EVM. Please consult the EVM User’s Guide prior to connecting any load to the EVM
output. If there is uncertainty as to the load specification, please contact a TI field representative.
During normal operation, some circuit components may have case temperatures greater than 60°C. The EVM
is designed to operate properly with certain components above 125°C as long as the input and output ranges
are maintained. These components include but are not limited to linear regulators, switching transistors, pass
transistors, and current sense resistors. These types of devices can be identified using the EVM schematic
located in the EVM User’s Guide. When placing measurement probes near these devices during operation,
please be aware that these devices may be very warm to the touch.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2001, Texas Instruments Incorporated

SLUU085 –November 2001
4UCC3580EVM
UCC3580EVM
Flyback Converters, Active Clamp vs Hard-Switched
Evaluation Board and List of Materials
Power Supply Control Products
Contents
1 Introduction 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Features 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Description 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Operating Guidelines 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Added Features 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Re-Configuration Instructions 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Test Setup and Test Points 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Application Drawings and Parts List 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1 Active Clamp Configuration 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2 Hard-Switched Configuration 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Traces and Silkscreen 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1 Traces 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2 Silkscreen 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Reference 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figures
1Recommended Test Setup for the UCC3580 Flyback Evaluation Board 7. . . . . . . . . . . . . . . . . . . . . . . . .
2Flyback Converter Populated for Active Clamp Operation 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3Flyback Converter Populated for Hard-Switched Operation 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4UCC3580EVM Layout, Top Traces 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5UCC3580EVM Layout, Bottom Traces 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6UCC3580EVM Silk Screen (only top layer has a silk screen) 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tables
1List of Test Points 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2Parts List for Active Clamp Configuration 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3Conversion From Active Clamp to Hard-Switched Configuration: Remove List 12. . . . . . . . . . . . . . . . .
4Conversion From Active Clamp to Hard-Switched Configuration: Add List 12. . . . . . . . . . . . . . . . . . . .

SLUU085 –November 2001
5
UCC3580EVM
1 Introduction
This user’s guide describes the UCC3580EVM flyback converter evaluation board for comparing an
active-clamp configuration with a hard-switched configuration. The UCC3580EVM is originally configured as
an active-clamp flyback converter. Instructions and parts list are included in order to reconfigure the
UCC3580EVM as a hard-switched flyback converter. Both configurations use the UCC3580 PWM controller.
The active clamp configuration operates noticeably more efficiently than the hard switched configuration. Most
of the efficiency differences will be seen in the primary-side components.
2 Features
DProvides auxiliary-switch activation complementary to main-power switch drive
DProgrammable dead time (turnon delay) between activation of each switch
DVoltage mode control with feedforward operation
DProgrammable limits for both transformer volt-second product and PWM duty cycle
DHigh-current gate driver for both main and auxiliary outputs
DMultiple protection features with latched shutdown and soft restart
DLow supply current (160-µA startup, 2.5-mA operation)
3 Description
3.1 Operating Guidelines
WARNING:
DANGER: HIGH VOLTAGE! This evaluation board is intended for professional use
only. It has exposed high voltages. Do not operate this board without proper
isolation and high-voltage/high-current safety practices.
Refer to the recommended test setup, as shown in Figure 1, and the test points in Table 1. Connect the
UCC3580EVM, configured for either active clamp operation or hard-switched operation, as shown in Figure 1.
Close the ac line switch and verify that the UCC3580EVM is operating correctly (12 V should be measured by
the hand-held DVM on the converter output). Using the appropriate oscilloscope probes, observe the main
transistor drain source voltage (TP14 to TP13) and the cathode to anode voltage of the output rectifier (TP6 to
TP8). The active clamp implementation will have crisp, clamped voltages and no overshoot on the output
rectifier. Converter dynamics can be observed [1] using TP3, 4 and 5.
Other test points are included to observe voltages and currents that are of interest for a specific application.
Table 1 describes the intended purpose of the test points that are installed in the board and how they should
be used.

SLUU085 –November 2001
6UCC3580EVM
3.2 Added Features
Flyback converters require a voltage clamp in order to limit the main switch voltage at turnoff. The effect is due
to energy that is stored in the primary leakage inductance of the power transformer. Older hard-switched
technology captures the excess leakage inductance energy at turnoff and merely dissipates it in a resistor. In
contrast, the active clamp uses the leakage inductance energy to facilitate zero voltage transitions. Efficient ZVS
transitions occur at turnon of both the main MOSFET and the auxiliary MOSFET.
Active-clamp technology is made possible here with the UCC3580 single ended active clamp/reset PWM
controller. Essentially, this controller is a voltage mode PWM controller with complementary outputs and
programmable delay between output transitions. The controller also includes over-current protection,
volt-seconds protection and a soft-start feature. The programmable delay is set to be long enough for the
leakage inductance energy to forward bias the power MOSFETs before their respective turnon, thus achieving
zero voltage switching.
The schematic for the active clamp configuration is shown in Figure 2 and its parts list is in Table 2. The
schematic for the hard-switched configuration is shown in Figure 3. Both configurations operate with the same
input voltage (110 VAC + 10%) and produce the same output voltage (12 V) and current (10 A). Heat sink HS1
is selected to accommodate the hard-switched configuration and it is thus over-sized for active clamp operation.
The thermal resistance of HS1 is 6.5°C/W, which is required for hard-switched operation. In contrast, heat sink
HS1 only needs a thermal resistance of 10°C/W for active-clamp operation, which was verified in the laboratory.
Thus transistor QM operates more efficiently, and it requires a smaller heat sink in the active-clamp
configuration. Also, notice that the active-clamp configuration does not require secondary rectifier snubber
components (R31 and C30). These features are the result of efficient active clamp technology.
For more information, pin descriptions and specifications for the UCC3580 single ended active clamp/reset
PWM, please refer to the UCC3580 data sheet.
3.3 Re-Configuration Instructions
WARNING:
Danger: Remove power from the UCC3580EVM before removing or installing
components.
These instructions describe how to reconfigure the UCC3580EVM from the active clamp configuration to the
hard switched configuration. This section requires components, de-soldering, soldering, and assembly
equipment and skills. The components are listed in Table 4.
Begin with an UCC3580EVM in the active-clamp configuration (original configuration). Refer to Table 3 and
Table 4 for the components to remove and add, respectively in order for the UCC3580EVM to match the
schematic in Figure 3. The additional components in Table 4 are supplied in the kit that is included with the
UCC3580EVM.
De-solder the components listed in Table 3. Solder the components listed in Table 4.
Conversion is now complete and comparisons can be made using the test setup in Figure 1 and the test points
in Table 1.

SLUU085 –November 2001
7
UCC3580EVM
4 Test Setup and Test Points
AC
LINE
AC
HIGH
AC
NEUTRAL
ISOLATION
TRANSFORMER
1:1
VARIAC
SAFETY
GROUND
1.2 Ω, minimum
120 Watts
10 Amps
Oscilloscope
Tektronix
TDS460A
Tektronix
P5205
100MHz
High Voltage
Differential
Probe
+–Tektronix
P5100 100X
Probe,
2500V,peak
Tektronix
P6138A
10X Probe,
300V,peak
1 2 3
NOTES:
1
2
3
Warning, High Voltage!
This test setup is connected to the ac
line, observe isolation requirements.
Use the P5202 for all differential observations,
both high and low voltage.
Use the P5100 for all voltage observations that
are more than 200V and ground referenced.
Use the P6138A for all voltage observations
that are less than 200V and ground
referenced.
J1–1
Chassis
J1–2
Neutral
J1–3
Line
J2–2
GND2
J2–1
+12V
Demonstration
Hand–Held DVM
+–
UCC3580EVM
Figure 1. Recommended Test Setup for the UCC3580EVM
Table 1. List of Test Points
Test Point Signal Name Voltage Range GND REF Measurement
TP1 GND2 SEC Secondary ground
TP2 12 V 12 V SEC 12 V, observe relative to TP1
TP3
TP4
TP5
12 V, 0.1 VAC SEC Injection and observation points for control loop. Refer to [1]
TP6
TP7
TP8
12 V
50 V
50 V
SEC Differentially observe V(D17) between TP6 and TP8.
Differentially observe snubber power between TP6 and TP7.
TP9 PRI GND PRI Primary ground for controller observations
TP10 OUT1 12 V PRI Main MOSFET (QM) gate control signal
TP11 OUT2 12 V PRI Auxiliary MOSFET (QA) gate control signal
TP12 EAOUT 5 V PRI Error amplifier output to PWM comparator
TP13 PRI GND PRI PRI GND reference for QM and CSENSE observations
TP14 DRAIN 300 V PRI Observe QM drain voltage relative to PRI GND
TP15 CSENSE 1 V PRI Observe drain current of QM
TP16
TP17
TP18
SOURCE
BULK
DRAIN
300 V
300 V
300 V
PRI Differentially observe QA drain–source voltage between TP18 and
TP16
Differentially observe clamp voltage, V(C25) between TP18 and TP17
TP19
TP20 PRI GND BULK 200 V PRI Observe bulk capacitor voltage ( the dc input voltage to the converter)

SLUU085 –November 2001
8UCC3580EVM
5 Application Drawings and Parts List
5.1 Active Clamp Configuration
UDG–00014
R7
3.92k R6
5.62k
C14
1µF
50V
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
IC1
UCC3580–4
DELAY
LINE
VDD
OUT1
PGND
OUT2
CLK
GND
SHDN
SS
REF
EAIN
EAOUT
OSC1
OSC2
RAMP
C9
680pF C8
470pF
R8
33.2k
R14
33.2k
R13
1.62k
TP12
EAOUT
C17
0.047µF
R17
130k R10
20.0k C12
0.01µF
R11 511k
R16
3.32k
D11
1N5819
C18
2200pF
R21 1k
R3
240k
1W
C10
330pF
500V
D7
1N5819
D6
1N5819
C15
0.1µFR4 47k
2W
W1
Q3
2N3904
R19
15 D9
1N5819
Q1
2N3906
R18
4.7k
R12
10k
QM
IRF740
HS1
R24
0.10
3W
M.E.
TP15
CSENSE
6 5 4
TP14
DRAIN
L3 16µH
2 4
D16
MUR460
TP9
PRI GND
C19
100µFD14
1N4744
R22 20
C24
0.1µF
D15
MUR120 3
4
3 TURNS
1 2
C21
0.1µF
400V
R23
10k
R15
4.7k
Q2
2N3904
Q4
2N3906
D10 1N4148
TP11
OUT2
T1
D5
1N4148
C6
0.1µF
R5 30
C11 0.1µF
TP10
OUT1
TP16
SOURCE
TP18
DRAIN
C25
0.068µF
400V
TP17
BULK 24
TURNS
158µH
TP20
BULK
C7
1000µF
TP19
TPI GND
+
R1
68k
1W
D2
1N5406
D1
1N5406
D4
1N5406
D3
1N5406
C2
4700pF
250V
C1
4700pF
250V
J1–1
CHASSIS
1 4
5 8
C4 0.1µF
250V
C5 0.1µF
250V
L1
18µH
R2
470k
C3 0.1µF
250V
F1 3A
J1–3
LINE J1–2
NEUTRAL
13 14 3 TURNS
2
C34
180µFC33
180µF
C32
180µFC31
180µF
++++
R31
NOT
USED
HS3
D17
MBRF2545CT
C30
NOT
USED
TP8
ANODE TP6
CATHODE
TP7
SNUB
TP12
+12V
TP1
GND2
TP4
TP5
R32
20
C29
470pF
R29
3.01k
R27
60.4k C28
4.7nF
R30
54.9k
C26
220pF
IC3
TL431 R28
14.3k
1
3 2
C27
1.0nF 250VAC
TP3
J2–2
RETURN
J2–1
+12V
IC2
CNY17–2
1 2
AC INPUT
115V 60Hz
CAUTION:
LINE VOLTAGE
3 1
PRIMARY SECONDARY
T2
L2
2mH
QA
IRF740
HS2
D13 1N4148
TP13
PRI GND
R26
3.01k
TH1
HIGH
TEMPERATURE–
SEE EVM WARNINGS
AND RESTRICTIONS
HIGH
TEMPERATURE–
SEE EVM WARNINGS
AND RESTRICTIONS
HIGH
TEMPERATURE–
SEE EVM WARNINGS
AND RESTRICTIONS
Note: High-temperature component. See EVM Warnings and Restrictions at the front of this document.
Figure 2. Flyback Converter Populated for Active Clamp Operation

SLUU085 –November 2001
9
UCC3580EVM
Table 2. Parts List for Active Clamp Configuration
Ref Des Qty Description MFG Size Part Number
C1,2 2 Y Cap, 4700 pF, 250 Vac Sprague 6.5 mm 5GAD47
C3 –C5 3X Film Cap, 0.1 µF, 250 Vac Philips 15 mm 222 330 40104
C6, C11,
C15, C24 4Ceramic, 0.1 µF, 50 V Panasonic 5 mm ECU–S1H104KBB
C7 1 Aluminum electrolytic, 1000 µF,
200 V United Chemi–con 10 mm KMH200VN102M35X35 T2
C8 1 Ceramic, 470 pF, 50 V Panasonic 2.5 mm ECU–S1H471JCA
C9 1 Ceramic, 680 pF, 50 V Panasonic 2.5 mm ECK–F1H681KB
C10 1 Ceramic Disk, 330 pF, 500 V Philips 5 mm D331K20Y5PLAAEU
C12 1 Ceramic, 0.01 µF, 50 V Panasonic 2.5 mm ECU–S1H103KBA
Ca
p
acitor
C14 1 Ceramic, 1 µF, 50 V Panasonic 5 mm ECU–S1H105MEB
C
apac
it
or C17 1Ceramic, 47 nF, 50 V Panasonic 2.5 mm ECU–S1H473MEA
C18 1 Ceramic, 2200 pF, 50 V Panasonic 2.5 mm ECK–F1H222KB
C19 1 Aluminum Electrolytic, 100 µF, 25 V Panasonic 2 mm ECE–A1EU101
C21 1 Foil, 0.1 µF, 400 V Panasonic 20 mm ECQ–P4104JU
C25 1 Foil, 0.068 µF, 400 V Panasonic 20 mm ECQ–P4683JU
C26 1 Ceramic, 220 pF, 50 V Panasonic 2.5 mm ECU–S1H221JCA
C27 1 Y1 Ceramic, 1000 pF, 250 Vac Panasonic 10 mm ECK–DNA102MB
C28 1 Ceramic, 4.7 nF, 50 V Panasonic 2.5 mm ECU–S1H472KBA
C29 1 Ceramic, 470 pF, 50 V Panasonic 7.5 mm ECU–S1H471JCA
C31 –C34 4Os–Con, 180 µF, 20 V Sanyo 5 mm 20SP180M
D1 –D4 4General Purpose, 3 A, 600 V DO–201AD 1N5406
D5, D10,
D13 3Switching, 75 mA, 75 V DO–35 1N4148
Diode
D6, D7,
D9, D11 4Schottky, 1 A, 40 V DO–41 1N5819
Di
o
d
eD14 1Zener, 15 V, 1 W DO–41 1N4744A
D15 1 Ultra Fast, 1 A, 200 V DO–41 MUR120
D16 1 Ultra Fast, 4 A, 400 V DO–201AD MUR460
D17 1 Schottky, Dual, 25 A, 45 V ITO–220AB MBRF2545CT
Fuse F1 1 3 A, AGC3A Buss, 3 A Buss 31.75 mm AGC3A
Fuse clips FCa,b 2 2 required, spacing per dwg Keystone 7.62 mm 3510
HS1 1 For QM, 6.5 C/W Thermalloy 50.44 mm 7022B–MT
Heatsink HS2 1For QA, 13 C/W Thermalloy 24.38 mm 6021PB
Heatsink
HS3 1 For D53, 4.4 C/W Thermalloy 27.94 mm 7023B–MT
PWM IC1 1 IC control TI–Unitrode DIL–16 UCC3580N–4
Optocoupler IC2 1 CNY17–2 DIL–6 CNY17–2
Voltage
Reference IC3 1 2.495 V TI TO–226AA TL431CLP
Connector J2 1 2 pos, 5.08 mm spacing Phoenix Contact 5.08 mm 1730612
L1 1 Toroid, 18 µH Magnetek 12.06 mm FIT68–7
Choke L2 1Common mode, 2 mH Panasonic 10X16.5 mm ELF–18N032A
Choke
L3 1 E25/10/6–3F3 core, 10-pins, 16 µHCentury Magnetics 5.1X15.6 mm CMI–2408
MOSFET QA, QM 2400 V, 0.55 Ω, 10 A IR TO–220AB IRF740

SLUU085 –November 2001
10 UCC3580EVM
Ref Des Qty Description MFG Size Part Number
Screw 3 #4–40 x 3/8”round head, philips, for QA, QM & D17
Nut 3#4–40 hex for QA, QM & D17
Washer 3#4, flat for QA, QM & D17
Washer 3#4, split lock, for QA, QM & D17
Heat sink pad 2TO220, for QA, QM Bergquist 3.18 mm
hole SP600–58
Shoulder
washer 2Hi temp plastic, for QA, QM & D17 Bivar for #4 screw SW–031–145
Tit
Q1, Q4 2PNP, 40 V, 200 mA TO–226AA 2N3906
Transistor Q2, Q3 2NPN, 40 V, 200 mA TO–226AA 2N3904
R1 1 1 W, Metal Oxide, 68 kΩ, 5% Panasonic 20 mm P68kW–1BK–ND
R2 1 1/4 W, carbon comp, 470 kΩ, 5% Multicomp 15.24 mm RC1/4G474JT
R3 1 1 W, Metal Oxide, 240 kΩ, 5% Panasonic 20 mm P240kW–1BK–ND
R4 1 2 W, 47 kΩ, 5% Panasonic 25.4 mm P47kW–2BK–ND
R5 1 1/4 W, 30 Ω, 5% 10.16 mm
R6 1 1/4 W, 5.62 kΩ, 1% 10.16 mm
R7 1 1/4 W, 3.92 kΩ, 1% 10.16 mm
R8 1 1/4 W, 33.2 kΩ, 1% 10.16 mm
R10 1 1/4 W, 20.0 kΩ, 1% 10.16 mm
R11 1 1/4 W, 511 kΩ, 1% 10.16 mm
R12, R23 21/4 W, 10 kΩ, 5% 10.16 mm
R13 1 1/4 W, 1.62 kΩ, 1% 10.16 mm
Resistor R14 11/4 W, 33.2 kΩ, 1% 10.16 mm
Resistor
R15 1 1/4 W, 4.7 kΩ, 5% 10.16 mm
R16 1 1/4 W, 3.32 kΩ, 1% 10.16 mm
R17 1 1/4 W, 130 kΩ, 1% 10.16 mm
R18 1 1/4 W, 4.7 kΩ, 5% 10.16 mm
R19 1 1/4 W, 15 Ω, 5% 10.16 mm
R21 1 1/4 W, 1 kΩ, 1% 10.16 mm
R22, R32 21/4 W, 20 Ω, 5% 10.16 mm
R24 1 3 W, Metal Element, 0.1 Ω, 1% IRC 20 mm LOB–3–0.10 Ω
R26, R29 21/4 W, 3.01 kΩ, 1% 10.16 mm
R27 1 1/4 W, 60.4 kΩ, 1% 10.16 mm
R28 1 1/4 W, 14.3 kΩ, 1% 10.16 mm
R30 1 1/4 W, 54.9 kΩ, 1% 10.16 mm
T1 1 Gate drive, 8-pins Coiltronics 2.5X8 mm CTX08–14086–X1
Transformer T2 1PC40EER35 core, 12-pins,
158 µH pri, 24:3 Century Magnetics 5X22.5 mm CMI–2409
Thermistor TH1 1 Jumper, insulated, 20AWG 10.16 mm
Test Point TP1 to
TP20 20 White, 0.063 inch dia. Keystone 1.6 mm 5012
Jumper W1 1 2 holes 7.62 mm
Support Post 4Nylon, in PWB corner holes Richco 156”hole,
15.9 mm SP3–10–01
PCB –– 12-Layer, 2 oz, 9.00”(L) x 6.00”(W) x 0.062”(T) SLUP054

SLUU085 –November 2001
11
UCC3580EVM
5.2 Hard-Switched Configuration
UDG–00015
HIGH
TEMPERATURE–
SEE EVM WARNINGS
AND RESTRICTIONS
R7
3.92k R6
5.62k
C14
1µF
50V
1
2
3
6
7
8
16
15
14
13
12
11
10
9
IC1
UCC3580–4
DELAY
LINE
VDD
OUT1
PGND
OUT2
CLK
GND
SHDN
SS
REF
EAIN
EAOUT
OSC1
OSC2
RAMP
C9
680pF C8
470pF
R8
33.2k
R14
33.2k
R13
1.62k
TP12
EAOUT
C17
0.047µF
R17
130k R10
20.0k C12
0.01µF
R11 511k
R16
3.32k
D11
1N5819
C18
2200pF
R21 1k
R3
240k
1W
C10
330pF
500V
D6
1N5819
C15
0.1µFR4
47k 2W
W1
Q3
2N3904
R19
15 D9
1N5819
Q1
2N3906
R18
4.7k
R12
10k
QM
IRF740
HS1
R24
0.10
3W
M.E.
TP15
CSENSE
6 5 4
TP14
DRAIN
D8
MUR160
TP13
PRI GND
TP9
PRI GND
C19
100µF
D14
1N4744 R22 20
C24
0.1µF
D15
MUR120 3
4
3 TURNS
1 2
C21
0.1µF
400V
TP11
OUT2
TP10
OUT1
TP16
SOURCE
TP18
DRAIN
C25
0.068µF
400V
TP17
BULK 24
TURNS
158µH
TP20
BULK
C7
1000µF
TP19
TPI GND
+
R1
68k
1W
D2
1N5406
D1
1N5406
D4
1N5406
D3
1N5406
C2
4700pF
250V
C1
4700pF
250V
J1–1
CHASSIS
C4 0.1µF
250V
C5 0.1µF
250V
L1
18µH
R2
470k
C3 0.1µF
250V
F1 3A
J1–3
LINE J1–2
NEUTRAL
13 14 3 TURNS
2
C34
180µFC33
180µF
C32
180µFC31
180µF
++++
R31
4.7
3W
HS3
D17
MBRF2545CT
C30
10nF
100V
TP8
ANODE TP6
CATHODE
TP7
SNUB
TP12
+12V
TP1
GND2
TP4 TP5
R32
20
C29
470pF
R29
3.01k
R27
60.4k C28
4.7nF
R30
54.9k
C26
220pF
IC3
TL431 R28
14.3k
1
3 2
C27
1.0nF 250VAC
TP3
J2–2
RETURN
J2–1
+12V
IC2
CNY17–2
1 2
AC INPUT
115V 60Hz
CAUTION:
LINE VOLTAGE
3 1
PRIMARY SECONDARY
T2
L2
2mH
D13 1N4148
D12
MUR160
L3 REPLACE WITH
JUMPER WIRE
14
R25
6.8k
5W
R9
2k
5W
C20
390pF
1kV
TH1
R26
3.01k
HIGH
TEMPERATURE–
SEE EVM WARNINGS
AND RESTRICTIONS
5
4
Note: High-temperature component. See EVM Warnings and Restrictions at the front of this document.
Figure 3. Flyback Converter Populated for Hard-Switched Operation

SLUU085 –November 2001
12 UCC3580EVM
Table 3. Conversion From Active Clamp to Hard-Switched Configuration: Remove List
Ref Des Qty Description MFG Size Part Number
Capacitor C6, C11 2Ceramic, 0.1 µF, 50 V Panasonic 5 mm ECU–S1H104KBB
D5, D10 2Switching, 75 mA, 75 V DO–35 1N4148
Diode D7, D11 2Schottky, 1 A, 40 V DO–41 1N5819
Diode
D16 1 Ultra Fast, 4 A, 400 V DO–201AD MUR460
Heatsink HS2 1 For QA, 13 C/W. Remove as an as-
sembly with QA and all of the mounting
hardware attached to HS2. Thermalloy 24.38 mm 6021PB
Choke L3 1 E25/10/6–3F3 core, 10-pins, 16 µHCentury Magnetics 5.1X15.6 mm CMI–2408
MOSFET QA 1 400 V, 0.55 Ω, 10 A (removed with
HS2) IR TO–220AB IRF740
Transistor
Q2 1 NPN, 40 V, 200 mA TO–226AA 2N3904
Transistor Q4 1PNP, 40 V, 200 mA TO–226AA 2N3906
R5 1 30 Ω, 1/4 w, 5% 10.16 mm
Resistor R15 11/4 W, 4.7 kΩ, 5% 10.16 mm
Resistor
R23 1 1/4 W, 10 kΩ, 5% 10.16 mm
Gate T1 1 xfmr, 8-pins Coiltronics 2.5X8 mm CTX08–14086–X1
Table 4. Conversion From Active Clamp to Hard-Switched Configuration: Add List
Ref Des Qty Description MFG Size Part Number
Capacitor
C20 1 Ceramic disk, 390 pF, 1 kV Panasonic 5 mm ECK–D3A391KBN
Capacitor C30 1Polyester, 0.01 µF, 100 V Panasonic 5 mm ECQ–E1103KF
Diode D8, D12 2Ultra fast, 1 A, 600 V DO–41 MUR160
Jumper L3 1 Pin 1 to pin 4, 20AWG, insulated 14 mm
R9 1 5 W, wire, vertical, 1 kΩ, 5% Ohmite 5 mm TWM–5J1K0
Resistor R25 15 W, wire, vertical, 6.8 kΩ, 5% Ohmite 5 mm TWM–5J6K8
Resistor
R31 1 5 W, wire, vertical, 4.7 Ω, 5% Ohmite 5 mm TWM–5J4R7

SLUU085 –November 2001
13
UCC3580EVM
6 Traces and silkscreen
Figures 4, 5, and 6 show the traces and silkscreen for the UCC3580EVM.
6.1 Traces
Figure 4. UCC3580EVM Layout, Top Traces
Figure 5. UCC3580EVM Layout, Bottom Traces

SLUU085 –November 2001
14 UCC3580EVM
6.2 Silkscreen
Figure 6. UCC3580EVM Silk Screen (only top layer has a silk screen)
7 Reference
[1] R.B. Ridley, Switching power supply design information, design tips, frequency response analyzers, and
educational material for power supplies. See web site located at http://www.ridleyengineering.com.

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